Image capturing apparatus and control method thereof

ABSTRACT

In an image capturing apparatus that allows input of instructions to the image capturing apparatus by shaking the apparatus, without using an operation unit, it is determined whether or not the image capturing apparatus is shaking. Then, in a case in which it is determined that the image capturing apparatus is shaking, at least some of the operations of the operation unit are invalidated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 13/194,304,filed Jul. 29, 2011 the entire disclosure of which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image capturing apparatus and acontrol method thereof.

2. Description of the Related Art

Image capturing apparatuses such as digital cameras and digital videocameras are provided with a variety of operation devices (buttons,switches, and the like). However, as such image capturing apparatuseshave become more compact, the installation space to accommodate theseoperation devices has become insufficient. It is possible to make theoperation devices more compact to fit the size of the installationspace, but there is a limit to how much operation devices can becompacted.

Accordingly, Japanese Patent Laid-Open No. 2000-125184 proposes an imagecapturing apparatus that accept input instructions without the use ofoperation devices, by utilizing a shake sensor provided for camera shakedetection.

The technology described in Japanese Patent Laid-Open No. 2000-125184allows instructions to be input using operation devices as well as byshaking the image capturing apparatus. And, input from the operationdevices is accepted even in a period in which shake is being detected.

Consequently, there is the problem that, when the user is shaking theimage capturing apparatus in order to input a desired instruction andaccidentally operates an operation device such as a menu button or thelike, an unintended instruction could be detected by the image capturingapparatus.

However, the technology described in Japanese Patent Laid-Open No.2000-125184 allows instructions to be input using operation devices aswell as by shaking the image capturing apparatus. And, input from theoperation devices is accepted even in a period in which shake is beingdetected.

Consequently, there is the problem that, when the user is shaking theimage capturing apparatus in order to input a desired instruction andaccidentally operates an operation device such as a menu button or thelike, an unintended instruction could be detected by the image capturingapparatus.

SUMMARY OF THE INVENTION

The present invention has been conceived in light of the problem in thebackground art as described above, and provides an image capturingapparatus or method which denies unintended instructions from beinginput to the image capturing apparatus even when the user is shaking theimage capturing apparatus in order to input a desired instruction andaccidentally operates an operation device such as a menu button or thelike.

In order to solve the above-mentioned problem, according to the presentinvention, there is provided an apparatus having an operation unit toenable a user to input an instruction to the apparatus, the apparatuscomprising: a shake detection unit that detects an acceleration of ashake applied to the apparatus; an operation detection unit that detectsa shake applied by a user in order to execute a predetermined processfrom output of the shake detection unit; and a control unit thatinvalidates operation of at least a portion of the operation unit when ashake applied by the user is detected.

According to another aspect of the present invention, there is providedan apparatus having an operation unit to enable a user to input aninstruction to the apparatus, the apparatus comprising: a shakedetection unit that detects an acceleration of a shake applied to theapparatus; an operation detection unit that detects a shake applied by auser in order to execute a predetermined process from output of theshake detection unit; and a control unit that invalidates operation ofat least a portion of the operation unit while a shake applied by theuser is being detected.

According to further aspect of the present invention, there is provideda control method for an apparatus having an operation unit to enable auser to input an instruction to the apparatus, the control methodcomprising: a shake detection step of detecting an acceleration of ashake applied to the apparatus; an operation detection step of detectinga shake applied by a user in order to execute a predetermined processfrom output from the shake detection step; and a control step ofinvalidating operation of at least a portion of the operation unit whena shake applied by the user is detected.

According to yet further aspect of the present invention, there isprovided a control method for an apparatus having an operation unit toenable a user to input an instruction to the apparatus, the controlmethod comprising: a shake detection step of detecting an accelerationcomponent of a shake applied to the apparatus; an operation detectionstep of detecting a shake applied by a user in order to execute apredetermined process from output from the shake detection step; and acontrol step of invalidating operation of at least a portion of theoperation unit while a shake applied by the user is being detected.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention and,together with the description, explain the principles of the invention.

FIG. 1 is a block diagram illustrating a functional configurationexample of a digital still camera as one example of an image capturingapparatus according to embodiments of the present invention;

FIG. 2A is a back surface view showing an example of the appearance ofthe camera according to embodiments of the present invention;

FIG. 2B is a front surface view showing an example of the appearance ofthe camera according to embodiments of the present invention uponsetting coordinate axes for the camera;

FIG. 3A is a diagram for explaining an operation of waving the cameraupward (degrees about a Z axis from a normal position;

FIG. 3B is a diagram for explaining directions of acceleration that anacceleration sensor of the camera according to embodiments of thepresent invention detects;

FIG. 3C is a diagram for explaining directions of acceleration that theacceleration sensor of the camera according to embodiments of thepresent invention detects;

FIG. 4A is a diagram showing an example of an output signal of theacceleration sensor when the camera according to embodiments of thepresent invention is waved upward a degrees about the Z axis from anormal position;

FIG. 4B is a diagram showing an example of the output signal of theacceleration sensor when the camera according to embodiments of thepresent invention is waved downward to a normal position from a positionwaved upward a degrees about the Z axis;

FIG. 4C is a diagram showing an example of the output signal of theacceleration sensor when the camera according to embodiments of thepresent invention is waved upward a degrees about the Z axis from thenormal position and then further waved downward to the normal positionfrom the position waved upward a degrees about the Z axis;

FIG. 5A is a diagram for explaining a detailed example of anacceleration waveform obtained by a waving operation of the presentinvention in the image capturing apparatus according to the presentinvention;

FIG. 5B is a diagram showing the change over time of the accelerationsignal when an offset component is removed from the acceleration outputsignal;

FIG. 6 is a flowchart for explaining outlines of a user operationrecognition process in an image capturing mode of the camera accordingto a first embodiment of the present invention;

FIG. 7 is a flowchart for explaining outlines of image feed and useroperation recognition processes in a reproduction mode of a cameraaccording to a second embodiment of the present invention;

FIG. 8A is a flowchart for explaining outlines of a user operationrecognition process in an image capturing mode of a camera according toa third embodiment of the present invention; and

FIG. 8B is a flowchart for explaining outlines of the user operationrecognition process in the image capturing mode of the camera accordingto the third embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the present invention will be described indetail in accordance with the accompanying drawings.

First Embodiment

FIG. 1 is a block diagram illustrating a functional configurationexample of a digital still camera (hereinafter referred to simply ascamera) as one example of an image capturing apparatus according to afirst embodiment of the present invention.

Incident light from a subject is focused by an optical system 1001composed of a lens and an aperture as a subject image on an imagecapturing surface of an image sensor 1003, which is a photoelectricconverter element such as a CCD or a CMOS image sensor. A mechanicalshutter 1002, under the control of a drive control unit 1007, opens andcloses a light path from the optical system 1001 to the image sensor1003.

A CDS circuit 1004 includes a correlated double sampling circuit andperforms analog signal processing such as correlated double sampling onanalog image signals output from the image sensor 1003. An A/D converter(A/D) 1005 converts the analog signals that the CDS circuit 1004 outputsinto digital signals. A timing signal generator 1006 generates signalsthat operate the drive control unit 1007, the image sensor 1003, the CDScircuit 1004 and the A/D converter 1005.

According to signals from the timing signal generator 1006, the drivecontrol unit 1007 drives aperture and autofocus mechanisms of theoptical system 1001, the mechanical shutter 1002, and the image sensor1003.

A signal processing unit 1008 performs signal processing such as colorinterpolation and white-balance processing on digital image data outputby the A/D converter 1005 in order to generate image data for displayand recording. An image memory 1009 stores image data processed by thesignal processing unit 1008. A recording control unit 1011 records imagedata output by the signal processing unit 1008 on a removable recordingmedium 1010 such as a memory card or the like that can be removed fromthe camera. The recording control unit 1011 also reads out image datarecorded on the recording medium 1010.

A display control unit 1013 generates signals for display from the imagedata output by the signal processing unit 1008 and displays them on animage display unit 1012. A system controller 1014 controls the entirecamera.

A nonvolatile memory (ROM) 1015 stores programs that describe thecontrol that the system controller 1014 carries out, control data suchas parameters, tables, and the like used when executing the programs,and correction data such as defective pixel addresses of the imagesensor 1003. When the system controller 1014 is running, the programsstored in the ROM 1015, the control data, and the correction data aresent to a RAM 1016.

An operation unit 1017 includes operation devices, such as buttons,switches, touch panels, and the like, to enable a user to inputinstructions to the camera. The operation unit 1017 also includes a modeswitch and can selectively set individual function modes such as apower-off mode, an image capturing mode, a reproduction mode, and a PCconnection mode.

A shake detection sensor 1018 is an acceleration sensor in the presentembodiment, and detects a shake applied to the camera. A shakedetermination unit 1019 determines the validity of instructions inputfrom the operation unit 1017 based on output from the shake detectionsensor 1018. A signal output unit 1020 detects a shake of the camerabased on the output from the shake detection sensor 1018, and from theinformation of the shake thus detected recognizes an instruction that isinput as the user shakes the camera. Although in the present embodimentan instruction is recognized depending on the direction of the detectedshake, other information about the shake, such as the size of the shakeand the number of shakes, may be taken into consideration as well. Then,based on the recognition results, the signal output unit 1020 outputs tothe system controller 1014 a signal that represents some instructionthat can be input by operating the operation devices included in theoperation unit 1017.

The signal output unit 1020 has, for example, a table, not shown, thatcorrelates information relating to shaking, such as the direction of theshake and the number of shakes, with corresponding instructions. Thesignal processing unit 1020 checks the table and recognizes theinstruction according to the information relating to the shake that isdetected based on the output of the shake detection sensor 1018. In thepresent embodiment, the signals that the signal output unit 1020 outputsto the system controller 1014 are the same signals as are output to thesystem controller 1014 when any of the operation devices of theoperation unit 1017 is operated. That is, in the camera of the presentembodiment, at least some of the instructions which can be input usingthe operation unit 1017 can also be input by shaking the camera in aparticular direction.

A portrait/landscape position detection sensor 1021, provided asnecessary, detects whether the camera is in portrait or landscapeposition, and outputs the detection results to the system controller1014. It is to be noted that the portrait/landscape position detectionsensor 1021 may also be used to detect shaking of the camera. In thiscase, the shake detection sensor 1018 is unnecessary.

Next, a description is given of an image capturing operation (a normalstill image capturing operation) using the mechanical shutter 1002 in acamera having a configuration like that described above.

Prior to the image capturing operation, when the system controller 1014is commencing operation (such as when the camera is powered on), thesystem controller 1014 transmits the necessary programs, control data,and correction data from the ROM 1015 to the RAM 1016 for storage. Inaddition, the system controller 1014 may transmit additional programsand control data as necessary from the ROM 1015 to the RAM 1016 for use,read out the data in the ROM 1015 directly for use, or the like.

FIG. 2A is a back surface view showing an example of the appearance ofthe camera according to embodiments of the present invention.

In the example shown in FIG. 2A, a release button 2001 and a zoom lever2002 for changing the focal length of a zoom lens of the optical system1001 are provided on an upper surface of the camera. In addition, a modedial 2003 for changing image capturing mode and a function button 2004including directional cursor and set keys for carrying out varioussettings are provided on a back surface of the camera. A menu button2005 for displaying various setting menus on the image display unit 1012and a display button 2006 for switching the display on the image displayunit 1012 are further provided on the back surface. These buttons,dials, and keys are all included in the operation unit 1017.

The release button 2001 has a structure such that, when depressedapproximately halfway, a first switch comes ON, and when fullydepressed, a second switch comes ON. When the first switch is turned ON,the system controller 1014 commences image capturing preparationoperations, including AE and AF processes. Then, the system controller1014 drives the aperture and lens of the optical system 1001 through thedrive control unit 1007 and forms a subject image of appropriatebrightness on the image sensor 1003. Then, when the second switch comesON, the system controller 1014 commences an image capturing operation(i.e., shoots for recording), opening the mechanical shutter 1002through the drive control unit 1007 for an appropriate exposure timebased on the AE and exposing the image sensor 1003. It is to be notedthat, in a case in which the image sensor 1003 has an electronic shutterfunction, it may be used together with the mechanical shutter 1002 tosecure the necessary exposure time.

The image sensor 1003 is driven by drive pulses generated from operatingpulses generated by the timing signal generator 1006, which iscontrolled by the system controller 1014, and photoelectrically convertsthe focused subject image into electrical signals that are then outputas analog image signals. Clock-synchronized noise is removed from theanalog image signals output from the image sensor 1003 at the CDScircuit 1004, which runs on operating pulses generated by the timingsignal generator 1006, and then the analog image signals are convertedinto digital image signals by the A/D converter 1005.

Next, at the signal processing unit 1008, which is controlled by thesystem controller 1014, the digital image signals output by the A/Dconverter 1005 are subjected to color conversion, white balance, gammacorrection and other image processing, resolution conversion processing,image compression processing and so forth to generate image data.

The image memory 1009 is used for temporarily storing digital imagesignals during processing by the signal processing unit 1008, storingimage data that is the signal-processed digital image signals, and thelike. The image data generated by the signal processing unit 1008 isconverted into data suitable for the recording medium 1010 (for example,file system data having a hierarchical structure) at the recordingcontrol unit 1011 and recorded on the recording medium 1010. Inaddition, the image data is converted into signals suitable for theimage display unit 1012 after resolution conversion by the signalprocessing unit 1008 at the display control unit 1013 (for example, NTSCformat analog signals) and displayed on the image display unit 1012.

At this point, the signal processing circuit 1008 may output the digitalimage signals as is as image data to the image memory 1009 or to therecording control unit 1011 depending on the control signals from thesystem controller 1014 without performing image processing on thedigital image signals. In a case in which there is a request from thesystem controller 1014, the signal processing unit 1008 outputs digitalimage signals and image data information produced during the course ofsignal processing, or information extracted from such information, tothe system controller 1014. Such information includes, for example,spatial frequency of the image, average pixel value within specifiedareas, data amount of the compressed image, and the like. Further, therecording control unit 1011 outputs information such as type and unusedcapacity of the recording medium 1010 to the system controller 1014 inresponse to a request from the system controller 1014.

When reproducing the image data recorded on the recording medium 1010,the recording control unit 1011 reads out the image data to bereproduced from the recording medium 1010 upon a control signal from thesystem controller 1014. Then, the signal processing unit 1008decompresses the image data if it is a compressed image and stores theimage data in the image memory 1009 in accordance with the controlsignal from the system controller 1014. The image data stored in theimage memory 1009, after it is converted to a display resolutionsuitable for the resolution of the image display unit 1012 by the signalprocessing unit 1008, is then converted into a signal suitable for theimage display unit 1012 at the display control unit 1013 and displayedon the image display unit 1012.

Next, a description is given of the shake determination unit 1019.

The shake detection sensor 1018 is, for example, in the presentembodiment, an acceleration sensor and detects an acceleration componentof a shake applied to the camera and detects a camera shake operation.The shake detection sensor 1018 is capable of independently detectingacceleration of the camera in each of three directions, an X-axisdirection, a Y-axis direction, and a Z-axis direction in a coordinationsystem shown in FIG. 2B (referred to as a camera coordinate systemhereinafter). The orientation of the camera shown in FIG. 2B is calledthe normal position. In this case, for example, the camera coordinatesystem can be defined as a coordinate system of which the Y axis directsto the counter direction in which the force of gravity is exerted, the Zaxis directs in parallel with the optical axis of the optical system1001, and the X axis directs to a direction orthogonal to the Y axis andthe Z axis (i.e., the horizontal direction).

It is to be noted that, if a shake in one or more particular directionscan be detected, there is no particular limitation on the type andnumber of sensors and their disposition. For example, in place of theacceleration sensor it is also possible to use an angular velocitysensor or a gravity sensor. It is to be noted that, in a case in whichthe camera has a camera shake detection sensor or the portrait/landscapeposition detection sensor 1021, these may be used as the shake detectionsensor of the present embodiment. In addition, although in FIG. 2B theorigin of the camera coordinate system is shown as coinciding with oneapex in a case in which a housing of the camera is considered to be arectangle, there are no particular limitations on the position of theorigin.

<Acceleration Detection Waveform in Waving/Shaking Operation>

Output signals indicating acceleration in the direction of each axisobtained by the shake detection sensor 1018 are input to the shakedetermination unit 1019. FIGS. 4A to 4C and 5A show examples of signalsinput to the shake determination unit 1019 from the shake detectionsensor 1018.

FIGS. 4A to 4C show signal waveforms showing changes over time inacceleration component in the X-axis direction detected by the shakedetection sensor 1018 when the camera is waved upward or downward. Theabscissa indicates time, and the ordinate indicates the accelerationcomponent detected when the camera is waved upward from a horizontalorientation.

FIG. 4A shows a signal waveform indicating change over time inacceleration component in the X-axis direction when the camera isaccelerated at the upward waving start timing from a horizontal state,is decelerated at the upward waving end timing, and is stopped. FIG. 4Acorresponds to a transition from a state 40 to a state 41 in FIG. 3A,and accelerations are detected in acceleration (peak 501) at the startof waving and in deceleration (peak 502) at the end of waving. Thecamera coordinate system shifts from a state shown in FIG. 3B to thatshown in FIG. 3C, so a gravitational acceleration component in theX-axis direction in a still state changes from 0 g level, as shown inFIG. 3B, to (sin α)·g level, as shown in FIG. 3C, before and afterwaving.

Also, FIG. 4B shows a signal waveform indicating change over time inacceleration component in the X-axis direction detected by the shakedetection sensor 1018 when the camera is accelerated and waved downwardfrom the state in which it is waved upward, is decelerated upon beingwaved downward to a horizontal position, and is stopped. That is, FIG.4B corresponds to a transition from a state 41 to a state 40 in FIG. 3A,and accelerations are detected in acceleration (peak 503) at the startof waving and in deceleration (peak 504) at the end of waving. Thecamera coordinate system shifts from a state shown in FIG. 3C to thatshown in FIG. 3B, so a gravitational acceleration component in theX-axis direction in a still state changes from (sin α)·g level, as shownin FIG. 3C, to 0 g level, as shown in FIG. 3B, before and after waving.

FIG. 4C shows a signal waveform indicating change over time inacceleration component in the X-axis direction detected by the shakedetection sensor 1018 when the camera is waved upward and then waveddownward. As can be seen from comparisons between FIGS. 4A to 4C, thesignal waveform shown in FIG. 4C is nearly the sum of the signalwaveforms shown in FIGS. 4A and 4B. A peak 505 shown in FIG. 4C is anacceleration peak that appears upon executing an upward wavingoperation. A peak 506 is an acceleration peak that appears uponcomposition of deceleration in upward waving and acceleration indownward waving, when downward waving is to be started after the end ofupward waving. A peak 507 is an acceleration peak that appears indeceleration at the end of the downward operation. The peak 505indicating the acceleration at the start of upward waving is defined asa first acceleration waveform, the peak 506 indicating the compositionof the accelerations at the end of upward waving and at the start ofdownward waving is defined as a second acceleration waveform, and thepeak 507 indicating the acceleration at the end of downward waving isdefined as a third acceleration waveform.

Among others, the peak 506 defined as the second acceleration waveformis likely to increase by a gravitational acceleration, and therefore canbe effectively used when a camera waving operation is detected based onthe acceleration. Although FIG. 4C shows the signal waveform of anacceleration detected upon an operation of waving the camera up once andthen waving it downward, a signal waveform out of phase with that shownin FIG. 4C is detected upon an operation of waving the camera downwardonce and then waving it upward.

FIG. 5A shows an example of the signal waveform of an accelerationcomponent in the X-axis direction detected by the shake detection sensor1018 (an acceleration sensor in the present embodiment) when the camerais waved upward and then waved downward, as in FIG. 4C. The abscissaindicates time, the ordinate indicates the output of the shake detectionsensor 1018, and each sign indicates the direction of acceleration.

Thresholds A and −A defined as first thresholds are used to determinewhether the camera in the present embodiment is moving. Morespecifically, the shake determination unit 1019 determines that thecamera is still if the absolute value of the acceleration detected bythe shake detection sensor 1018 falls within the range of the thresholdA or less, and determines that the camera is moving if the absolutevalue of the acceleration is equal to or larger than the firstthreshold.

Also, thresholds B and −B defined as second thresholds are used todetermine whether the camera is waved with predetermined wavingcharacteristics. The thresholds A, −A, B, and −B are set to satisfyrelations: Threshold −B<Threshold −A and Threshold A<Threshold B. If theabsolute value of the acceleration detected by the shake detectionsensor 1018 is greater or equal to the threshold A and is smaller thanthe threshold B, the shake determination unit 1019 determines that thecamera is moving but is not waved with predetermined wavingcharacteristics. On the other hand, if the absolute value of theacceleration detected by the shake detection sensor 1018 is greater orequal to the threshold B, the shake determination unit 1019 determinesthat the camera is moving and is waved with predetermined wavingcharacteristics.

Moreover, thresholds C and −C defined as third thresholds are used todetermine whether the camera is waved within a predetermined strengthrange. The thresholds B, −B, C, and −C are set to satisfy relations:Threshold −C<Threshold −B and Threshold B<Threshold C. If the absolutevalue of the acceleration detected by the shake detection sensor 1018 isequal to or larger than the threshold B and is smaller than thethreshold C, the shake determination unit 1019 determines that thecamera is waved with predetermined waving characteristics within apredetermined strength range. On the other hand, if the absolute valueof the acceleration detected by the shake detection sensor 1018 is equalto or larger than the threshold C, the shake determination unit 1019determines that the camera is waved too strongly. When the camera iswaved strongly, the possibility that the user falls it off his or herhand by mistake increases, so a warning is issued if it is determinedthat the camera is waved too strongly. As a warning method, a warningmessage may be displayed on the image display unit 1012 or a warningsound may be generated by a loudspeaker.

The shake determination unit 1019 may compare the acceleration detectedby the shake detection sensor 1018 with positive and negativethresholds, instead of comparing the absolute value of the accelerationvalue with thresholds having the same absolute value. Assume, forexample, that the shake determination unit 1019 compares the detectedacceleration with the first thresholds. If the detected acceleration isfrom −A (exclusive) to +A (exclusive), the shake determination unit 1019determines that the camera is still (is not waved). On the other hand,if the detected acceleration is −A or less or +A or more, the shakedetermination unit 1019 determines that the camera is moving. The sameholds true for the remaining thresholds.

Because the camera is likely to be waved more strongly in a targetedoperation than in its preparation operation, a peak 302 with the largestabsolute value of the acceleration among peaks 301 to 303 in the signalwaveform shown in FIG. 5A corresponds to the second accelerationwaveform shown in FIG. 4C. In other words, the signal waveform indicatesa downward waving operation when an operation of waving the cameradownward is targeted, and an upward waving operation when an operationof waving the camera upward is targeted. In this case, the peak 301corresponds to the first acceleration waveform shown in FIG. 4C, andindicates acceleration in an upward waving operation that is a downwardwaving preparation operation if the targeted operation is downwardwaving. Also, the peak 303 corresponds to the third accelerationwaveform shown in FIG. 4C, and indicates a waveform obtained upondetecting deceleration in downward waving. If the targeted operation isan upward waving operation, the waveform is bilaterally symmetricalabout the X axis (has opposite signs with respect to the X axis), so thefirst acceleration waveform 301 and third acceleration waveform 303indicate upward waving. It is to be noted that a waveform with thelargest absolute value of the acceleration does not always indicate atargeted operation. A method of detecting a targeted operation in thepresent invention will be described later.

Reference numeral 310 denotes a time point when the first accelerationwaveform 301 crosses over the threshold A (or the threshold −A).Reference numeral 311 denotes a time point when the second accelerationwaveform 302 crosses over the threshold A (or the threshold −A) for thefirst time; and 313, a time point when the second acceleration waveform302 crosses over the threshold A (or the threshold −A) again. Referencenumeral 314 denotes a time point when the third acceleration waveform303 crosses over the threshold A (or the threshold −A) again aftercrossing it over once. Thresholds S1 and S2 are thresholds in a durationt1 in which the second acceleration waveform indicating a targetedoperation (main operation) is kept greater or equal to the threshold Aor smaller or equal to the threshold −A. That is, the duration t1 isfrom when the second acceleration waveform 302 becomes greater or equalto the threshold A until it becomes equal to the threshold A again (orfrom when it becomes smaller or equal to the threshold −A until itbecomes equal to the threshold −A again). In the present embodiment, ifa condition: Threshold S1≦Duration t1≦Threshold S2 is satisfied, theshake determination unit 1019 determines that a second accelerationwaveform (main operation) is detected.

Also, if the camera is kept in a state, in which it is determined to bestill (a state in which the acceleration is from the threshold −A(exclusive) to the threshold A (exclusive)), for a time equal to orlonger than a threshold E, the shake determination unit 1019 determinesthat the camera is at a position at which a waving operation is stopped.In this case, if the camera is kept in a state in which it is determinedto be still for a time shorter than the threshold E, the shakedetermination unit 1019 determines that an operation started at a timepoint when the acceleration becomes greater or equal to the threshold Aor smaller or equal to the threshold −A for the first time continues(one waving operation is done).

Therefore, the shake determination unit 1019 determines that, forexample, the third acceleration waveform 303 shown in FIG. 5A indicatesan operation continuous with those indicated by the first accelerationwaveform 301 and second acceleration waveform 302. If a state in whichthe acceleration is from the threshold −A (exclusive) to the threshold A(exclusive) continues for a time equal to or longer than the threshold Efrom the time point 314, and then the acceleration becomes smaller orequal to the threshold −A or greater or equal to the threshold A again,the shake determination unit 1019 determines that a new operation isstarted.

Although three thresholds A, B, and C, each having the same absolutevalue, are used as thresholds for the acceleration level in FIG. 5A, oneor more of positive and negative thresholds may have different absolutevalues.

FIG. 5B is a diagram showing change over time in a rate of change in theacceleration signal when an offset component is removed from theacceleration output signal shown in FIG. 5A. The rate of change in theacceleration signal may be used as the threshold used to determinewhether the camera is moving or still, having been described withreference to FIG. 5A. In this case, thresholds THh and THl are used inplace of the thresholds ±A in FIG. 5A. It is to be noted that thresholdsTHh and THl may be used in place of the thresholds ±B or ±C in FIG. 5A,and a threshold for the rate of change in the acceleration signal may beseparately determined.

Based on the acceleration signal output or the rate of change in theacceleration signal in the direction of a given axis as shown in FIG. 5Aor in FIG. 5B, the shake determination unit 1019 determines whether ornot the camera is shaking along that axis and outputs the results ofthat determination to the system controller 1014. Based on the resultsof the determination, the system controller 1014 validates orinvalidates operation of the camera by the operation devices included inthe operation unit 1017.

<User Operation Recognition Process>

FIG. 6 is a flowchart illustrating outlines of a user operationrecognition process during image capture standby of the camera accordingto the present embodiment.

First, from the acceleration output signals in the X-axis direction ofthe shake detection sensor 1018, the shake determination unit 1019determines whether or not the camera is shaking in the X-axis direction(S8001). The shake determination unit 1019, using, for example, thesize, direction, and frequency of peaks in the acceleration signaloutput or the acceleration signal rate of change in the X-axis directionas a reference, determines whether or not the camera is shaking in theX-axis direction.

More specifically, as an example, the shake determination unit 1019determines that the camera is shaking in the X-axis direction whenevereither a state that satisfies the following two criteria continues for acertain period of time or a predetermined number of consecutive peakssatisfy the same two criteria:

(1) a period during which peaks in the acceleration signal output or therate of change in the acceleration signal in the X-axis direction areoutside a predetermined threshold range (from A to −A when theacceleration signal output is used, or from THh to THl when the rate ofchange in the acceleration signal is used) is equal to or less than apredetermined period; and

(2) consecutive peaks are reversed.

As another example, the shake determination unit 1019

(a) determines that a shake is detected if the rate of change in theacceleration signal in the X-axis direction falls outside apredetermined threshold range (for example, the range of the thresholds±A in FIG. 5A); and(b) determines that a waving operation is stopped when a state in whichthe rate of change in the acceleration signal in the X-axis directionfalls within the predetermined threshold range continues for apredetermined time (for example, the threshold E in FIG. 5A) or moreafter it is determined in (a) that a shake is detected.

During the time from the state defined by (a) to that defined by (b),even if the rate of change in the acceleration signal in the X-axisdirection falls within the predetermined threshold range (for example,the range of the thresholds ±A in FIG. 5A), it is determined that anoperation is in progress.

By contrast, in the event that these criteria are not satisfied, theshake determination unit 1019 determines that the camera is not shakingin the X-axis direction. The shake determination unit 1019 can also makethe same determination for the Y-axis direction and the Z-axisdirection. It is to be noted that the above-described shakedetermination method is but one example thereof, and other methods maybe used to determine the presence or absence of a shake.

If it is determined that the camera is not shaking in the X-axisdirection, the shake determination unit 1019 determines whether or notthe camera is shaking in the Y-axis direction from the accelerationoutput signals in the Y-axis direction of the shake detection sensor1018 (S8002).

If it is determined that the camera is not shaking in the Y-axisdirection either, the shake determination unit 1019 determines whetheror not the camera is shaking in the Z-axis direction from theacceleration output signals in the Z-axis direction of the shakedetection sensor 1018 (S8003).

The shake determination unit 1019 outputs the determination resultsalong each axis to the system controller 1014. Then, in the event thatdetermination results are obtained which indicate shaking in thedirection of any of the axes, the system controller 1014 invalidatesoperation of the camera by the operation unit 1017 (S8005). Whenoperations by the operation unit 1017 are invalidated, the systemcontroller 1014 ignores input from the operation unit 1017. By so doing,even when (for example) the user in attempting to input a desiredinstruction shakes the camera and accidentally operates the menu button2005, the mode dial 2003 or the like of the operation unit 1017,unintended input through the operation unit 1017 can be prevented.

However, in the present embodiment, operation of the release button2001, in particular the second switch coming ON, is not ignored by thesystem controller 1014 even when operation by the operation unit 1017 isinvalidated. Whether operation by the operation unit 1017 is valid orinvalid can, for example, be stored as a flag in the RAM 1016.

It is to be noted that, although not specifically described in theflowchart shown in FIG. 6, in a case in which a shake in the directionof a particular axis is recognized as input of a command or aninstruction, the system controller 1014 carries out a recognitionprocess based on the detection results output by the shake determinationunit 1019. Then, the system controller 1014 executes an operationaccording to the recognized command or instruction.

The shake determination unit 1019 may output the determination resultsat every determination along each of the axes, or it may output acombined determination for all the axes. In addition, the shakedetermination unit 1019 may output determination results only along thataxis or axes along which it is determined that there is shaking (thatis, if there is no axis along which it is determined that there isshaking, no determination result is output). Alternatively, in a case inwhich it is determined that there is shaking along an axis, the shakedetermination unit 1019 may omit determination processing for theremaining axes (excluding those instances in which a particularcombination of shaking directions is set to be recognized as input of aninstruction).

If it is determined that the camera is not shaking along any of theaxes, the system controller 1014 validates operation of the camera bythe operation unit 1017 (S8004). It is to be noted that, normally, theoperation unit 1017 is valid. Accordingly, unless operation of theoperation unit 1017 has been invalidated, it is not particularlynecessary for the system controller 1014 to carry out processing for thepurpose of validating its operation in S8004.

The system controller 1014 determines whether or not an instruction tocommence image capturing has been input, that is, the system controller1014 determines whether or not the second switch of the release button2001 is ON (S8006). If the second switch is OFF, processing is repeatedfrom S8001. When the second switch is ON, the system controller 1014carries out the image capturing process even if operation of the cameraby the operation unit 1017 is invalidated (S8007).

In other words, in the camera of the present embodiment, in a case inwhich it is detected that the second switch of the release button 2001is ON, image capturing is executed. This is because there is a strongpossibility that a full stroke operation of the release button 2001, bywhich the second switch comes ON, is likely to be not a mistakenoperation but an intentional operation. By contrast, the first switchcoming ON by a half stroke operation of the release button 2001 isignored when the operation unit 1017 is invalidated. However, so long asthe first switch is maintained in the ON state a shake of the cameraalong any of the X axis, Y axis, and Z axis is no longer detected, andonce operation of the camera by the operation unit 1017 is validated,the coming ON of the first switch is validated as well. Then, the systemcontroller 1014, in response to the coming ON of the first switch,commences such image capturing preparation operations as AE and AF.

Thus, as described above, in a camera that allows input of instructionsand commands by shaking the apparatus, the present invention can reduceinput of instructions that a user does not intend by unintendedoperation of buttons or keys when the apparatus is being shaken.

Second Embodiment

A distinctive feature of the present embodiment is that the user waves aportable device (for example, a camera in which at least one of areproduction mode and an image capturing mode is settable) to enable aninstruction of forward feed and backward feed of an image reproduced bythe portable device. The user can watch an image recorded on a recordingmedium 1010 through, for example, an image display unit 1012 by, forexample, setting the portable device in the reproduction mode. It is tobe noted that the camera having been described in the first embodimentis used as an example of the portable device according to the presentembodiment. Therefore, a description of, for example, a hardwareconfiguration and a waving operation detection method is omitted. In thepresent embodiment as well, determination associated with a camerawaving operation is performed by detecting an acceleration in the X-axisdirection.

FIG. 7 is a flowchart for explaining a process associated with onewaving operation. First, a system controller 1014 determines whether thecamera is set in the reproduction mode (S700). If it is determined thatthe reproduction mode is set, the system controller 1014 executesprocesses in S701 and subsequent steps. If the acceleration detected bya shake detection sensor 1018 crosses over the threshold A or −A in FIG.5A (the time point 310 shown in FIG. 5A), a shake determination unit1019 detects that the camera has moved (S701). If the shakedetermination unit 1019 detects that the camera has moved (is waved),the system controller 1014 invalidates operation of the camera by anoperation unit 1017 (S702).

Acceleration detection is performed in a predetermined detection periodof the shake detection sensor 1018. Also, the shake determination unit1019 stores the detection value obtained by the shake detection sensor1018, and updates the peak value (minimum value) stored every time theprevious peak value (minimum value) is updated to the detection valueobtained for every detection period after the detection value fallsbelow the threshold −A at the time point 310. Therefore, the shakedetermination unit 1019 can measure the peak value (minimum value) ofthe detection value after the detection value falls below the threshold−A. The shake determination unit 1019 can also measure the upward peakvalue (minimum value) in the same way.

When it is detected in S701 that the camera has moved, and a process ofdetecting an operation commences in S702, the shake determination unit1019 detects a first acceleration waveform first. When the accelerationdetected by the shake detection sensor 1018 crosses over the threshold Aor −A after it is detected that the camera has moved, the shakedetermination unit 1019 determines that a first acceleration waveform isdetected.

When a first acceleration waveform is detected, the shake determinationunit 1019 performs a process of detecting a second acceleration waveformnext. When the detected acceleration crosses over the threshold A (orthe threshold −A) (time point 311), the shake determination unit 1019detects the start of a second acceleration waveform. When the detectedacceleration crosses over the threshold A (or the threshold −A) again inthe duration t1 which satisfies a condition: Threshold S1≦Durationt1≦Threshold S2 (time point 313), the shake determination unit 1019detects the end of the second acceleration waveform. As described above,if the duration t1 does not satisfy the above-mentioned condition, theshake determination unit 1019 does not determine that a secondacceleration waveform is detected. Further, if the detected accelerationcrosses over the threshold B (or the threshold −B) (time point 312) anddoes not reach the threshold C (or the threshold −C) from the time point311 to the time point 313, the shake determination unit 1019 determinesthat the camera is waved correctly (waved with a predetermined strength)(Yes in S703).

Also, based on the sign of the threshold B over which the secondacceleration waveform crosses, the shake determination unit 1019discriminates whether the camera is waved upward or downward. On theother hand, if the second acceleration waveform does not cross over thethreshold B (or the threshold −B) or reaches the threshold C (or thethreshold −C), the shake determination unit 1019 determines that thecamera is not waved correctly (No in S703). In this case, the shakedetermination unit 1019 discriminates in S710 whether the magnitude ofthe waving operation (the magnitude of detected acceleration) is largerthan a predetermined value (the thresholds ±C in FIG. 5). If the peakvalue of the second acceleration waveform falls below the threshold B(or the threshold −B), the shake determination unit 1019 ends wavingoperation detection (S708). The system controller 1014 validatesoperation by the operation unit 1017 (S709). On the other hand, if thepeak value of the second acceleration waveform reaches the threshold C(or the threshold −C), the shake determination unit 1019 issues awarning, as described above (S710). Processes in S708 and subsequentsteps are as described above.

It is to be noted that a second acceleration waveform needs to bedetected based on a threshold which is different in sign from that usedin detecting a first acceleration waveform. If, for example, a firstacceleration waveform is detected based on the threshold −A (if a firstacceleration waveform with a concave peak is detected), a secondacceleration waveform needs to be detected based on the threshold A.This is because the first acceleration waveform corresponds to apreparation operation before a main operation, and the main operation isreverse to the preparation operation.

If the shake determination unit 1019 determines in S703 that the camerais waved correctly, the system controller 1014 changes the imagedisplayed on the image display unit 1012 via a display control unit 1013at the time point at which the end of the second acceleration waveformis detected (S704). The end of the second acceleration waveform isdetected at the time point (the time point 313 shown in FIG. 5) at whichthe second acceleration waveform crosses over the threshold A (or thethreshold −A) again. In changing the image to be displayed, images maybe changed in the order of file name or number, in the order of imagecapturing date/time, or in the order of date/time recorded on therecording medium 1010. The order of change in image may be switchedbetween the forward and backward directions, depending on the sign ofthe threshold used in detecting a first or second acceleration waveform.Nevertheless, when a mode in which images are displayed in random order,as in random reproduction, is set, the image to be displayed is changedindependently of the sign of the threshold.

In S705, the shake determination unit 1019 determines whether theacceleration detected by the shake detection sensor 1018 falls withinthe range of the threshold −A (exclusive) to the threshold A(exclusive). While the detected acceleration is kept within the range ofthe threshold −A (exclusive) to the threshold A (exclusive), the shakedetermination unit 1019 measures a shake duration t2 (S706). The shakedetermination unit 1019 determines whether the shake duration t2 isequal to or longer than a threshold E (S707). If the shake duration t2is equal to or longer than the threshold E, the shake determination unit1019 determines that the camera has come to rest, and waving operationdetection ends (S708). The system controller 1014 validates operation bythe operation unit 1017 (S709).

In this manner, operation of the camera by the operation unit 1017 isnot validated unless a state in which the magnitude (absolute value) ofthe acceleration is smaller than a predetermined value continues for apredetermined time or more after it is determined that the camera hasmoved. In the example shown in FIG. 5A, the shake determination unit1019 determines that a waving operation is in progress until thepredetermined time E elapses from the time point 310 to a time point314. Therefore, even if the acceleration signal output in the X-axisdirection falls within the range of the thresholds ±A, operation by theoperation unit 1017 is invalidated until that state continues for a timeequal to the threshold E.

On the other hand, if it is determined in S705 that the detectedacceleration is smaller or equal to the threshold −A or greater or equalto threshold A, the shake determination unit 1019 initializes the shakeduration t2 (S712). The process returns to S705, in which the shakedetermination unit 1019 again determines whether the absolute value ofthe detected acceleration falls within the range of less than thethreshold A.

Also, if the absolute value of the detected acceleration is smaller thanthe threshold A, but the shake duration t2 is less than the threshold E(No in S707), the shake determination unit 1019 repeats the processes inS705 and subsequent steps while incrementing the value of the shakeduration t2.

As described above, in the present embodiment, even if the absolutevalue of the detected acceleration is smaller than a first threshold(smaller than the threshold A), unless this state continues for a timeequal to or longer than the threshold E, it is determined that anoperation from the time point at which the detected acceleration reachesthe threshold A or −A first continues (one waving operation is done).This makes it possible to prevent determination that a thirdacceleration waveform corresponds to a new waving operation.

When the detected acceleration of the camera according to the presentembodiment is greater or equal to a predetermined value but nonethelessacts in a timeframe that is too short or too long, or acts strongly, anerror is determined to prevent detection that a waving operation is inprogress. Thus, a waveform is detected with higher precision to providean intuitive, friendly operation system. Also, if a still state does notcontinue for a predetermined time or longer, it is determined that onewaving operation continues, thereby making it possible to preciselydetect first, second, and third acceleration waveforms corresponding toa series of operations from a preparation operation to a main operation.

As has been described above, according to the present embodiment, it ispossible to provide a camera which can change an image by waving thecamera in a specific direction while this image is displayed, as in, forexample, a reproduction mode. Also, even if the user operates theoperation unit by mistake in a camera waving operation, unintendedinstructions are not reflected.

In the present embodiment, a case in which a function of changing thedisplay image is assigned to a waving operation while the image isdisplayed in the reproduction mode has been taken as an example of aprocess for detecting a waving operation. However, the same detectingprocess can be performed when a function associated with image capturingin the image capturing mode is assigned to a waving operation as well.That is, once it is determined that the camera has moved, operation bythe operation unit is not validated unless a state in which themagnitude (absolute value) of the acceleration is smaller than apredetermined value continues for a predetermined time or more.

Also, in the first embodiment, image capturing is executed when it isdetected that the second switch of the release button 2001 is ON. Incontrast to this, in the present embodiment, the camera may shift fromthe reproduction mode to the image capturing mode when a release button2001 is operated in, for example, the reproduction mode. At this time,the first switch coming ON by a half stroke operation of the releasebutton 2001 may be ignored in the reproduction mode, and a shift fromthe reproduction mode to the image capturing mode may be made when it isdetected that the second switch of the release button 2001 is ON. Inthis case, so long as the first switch is maintained in the ON state ashake of the camera along any of the X axis, Y axis, and Z axis is nolonger detected, and once operation of the camera by the operation unit1017 is validated, the coming ON of the first switch is validated aswell.

Third Embodiment

Next, a description is given of a third embodiment of the presentinvention. The configuration of the camera of the present embodiment canbe the same as that of the first embodiment, and therefore a descriptionof the configuration thereof is omitted. A distinctive feature thepresent embodiment is that, depending on the position of the camera(portrait position or landscape position) and the direction of the shakethat is detected, of the operation unit 1017, validation/invalidation ofthose operation devices that are provided on the upper surface of thecamera and those operation devices that are provided on the back surfaceof the camera is carried out separately. It is to be noted that, in thepresent embodiment, the operation devices to be validated/invalidatedneed not be those provided on the upper surface or the back surface ofthe camera but may be operation devices provided on any surface of thehousing of the camera. That is, the present embodiment is applicable tooperation devices provided on any one surface and on another surface ofoperation devices provided on at least two surfaces of the camerahousing.

FIGS. 8A and 8B are flowcharts for explaining outlines of a useroperation recognition process in an image capturing mode of a cameraaccording to the third embodiment of the present invention.

First, the system controller 1014 determines the orientation of thecamera from the output of the portrait/landscape position detectionsensor 1021 (S9001). At this point, if the camera is at the normalposition or the reverse position (a position rotated 180 degrees aboutthe optical axis of the optical system 1001 with respect to the normalposition), the shake determination unit 1019 determines whether or notthe camera is shaking in the X-axis direction (S9002). If it isdetermined that camera is shaking in the X-axis direction, then of theoperation devices included in the operation unit 1017 the systemcontroller 1014 invalidates operation of those provided on the uppersurface of the camera and validates operation of those provided on theback surface of the camera (S9003). This is done because, in a case inwhich the camera is being shaken in the X-axis direction, there is astrong possibility that the operation devices provided on the uppersurface of the camera have been operated accidentally.

Next, the system controller 1014 determines whether or not the secondswitch of the release button 2001 is ON (S9004), and if it is, carriesout an image capturing operation (S9008). If the second switch of therelease button 2001 is OFF, the system controller 1014 determineswhether or not operation devices on the upper surface of the camera havebeen operated (S9005). If operation devices on the upper surface of thecamera have not been operated, the system controller 1014 returnsprocessing to the camera orientation determination step (S9001).

On the other hand, if operation devices on the upper surface of thecamera have been operated, the system controller 1014 determines whetheror not the second switch of the release button 2001 is ON (S9006), andif it is, carries out an image capturing operation (S9008). If thesecond switch of the release button 2001 is OFF, the system controller1014 determines whether or not a predetermined time has lapsed sinceoperation of the operation devices on the upper surface of the camerawas detected in S9005 (S9007). If the predetermined time period has notlapsed, the system controller 1014 continues the determination step ofS9006. If the predetermined time has lapsed, the system controller 1014returns processing to the camera orientation determination step (S9001).

At S9002, in a case in which a determination that the camera is shakingin the X-axis direction has not been obtained, the shake determinationunit 1019 determines whether or not the camera is shaking in the Y-axisor Z-axis directions (S9009). If it is determined that the camera is notshaking in either the Y-axis or the Z-axis directions, the systemcontroller 1014 validates operation of all the operation devicesincluded in the operation unit 1017 (S9013) and returns processing toS9001. On the other hand, if it is determined that the camera is shakingin the Y-axis or the Z-axis directions, the system controller 1014validates operation of the operation devices provided on the uppersurface of the camera and invalidates operation of the operation devicesprovided on the back surface of the camera (S9010). This is donebecause, in a case in which the camera is being shaken in the Y-axis orthe Z-axis directions, there is a strong possibility that the operationdevices provided on the back surface of the camera have been operatedaccidentally.

Next, the system controller 1014 determines whether or not the secondswitch of the release button 2001 is ON (S9011), and if it is, carriesout an image capturing operation (S9008). If the second switch of therelease button 2001 is OFF, the system controller 1014 determines ifoperation devices on the back surface of the camera have been operated(S9012). If operation devices on the back surface of the camera have notbeen operated, the system controller 1014 returns processing to thecamera orientation determination step (S9001).

If operation devices on the back surface of the camera have beenoperated, the system controller 1014 executes the processes from S9006onwards described above.

In S9001, in the event that the orientation of the camera is other thanthe normal position or the reversed position, then it is likely that thecamera orientation is such that the camera grip is at the top or at thebottom (typically, positions rotated 90 degrees or −90 degrees about theoptical axis of the lens from the normal position). In this case,whether or not the camera is being shaken in one of the X-axis, Y-axis,or Z-axis directions is determined by the shake determination unit 1019(S9014). If no shake is detected along any of these axes, the systemcontroller 1014 validates operation of all the operation devicesincluded in the operation unit 1017 (S9013) and returns processing toS9001. On the other hand, if shake is detected along any of these axes,the system controller 1014 validates operation of the operation devicesprovided on the upper surface of the camera and invalidates operation ofthe operation devices provided on the back surface of the camera(S9015). This is done because, in a case in which the camera orientationis such that the camera grip is that the top or at the bottom, if thecamera is being shaken in any one of these directions, there is a strongpossibility that the operation devices provided on the back surface ofthe camera have been operated accidentally.

Thereafter, at S9016 and S9017, the system controller 1014 carries outthe same processes as those in S9011 and S9012.

Thus, as described above, in the present embodiment,validation/invalidation of operation of the operation devices providedon the upper surface of the camera and operation of the operationdevices provided on the back surface of the camera is carried outseparately depending on the orientation of the camera and the directionof shake of the camera. As a result, in addition to the effect the firstembodiment, it becomes possible to carry out fine control,distinguishing between operation devices susceptible to accidentaloperation and operation devices not susceptible to accidental operation.

It is to be noted that in the present embodiment also, as in the firstembodiment, in a case in which shaking in the X-axis, Y-axis, or Z-axisdirections is detected in S9002 and S9009, the system controller 1014may recognize it as an instruction or a command correlated in advancewith the direction of the shaking (or a combination thereof). Then, thesystem controller 1014 executes an operation corresponding to therecognized instruction or command.

Modification of Third Embodiment

As a modification of the third embodiment, a mode in which the secondand third embodiments are combined is also available in the reproductionmode. That is, a method of invalidating operation by the operationdevice of the camera in accordance with the orientation and wavingdirection, as in the third embodiment, is available. In this case, thetime in which a waving operation is detected is determined as theinvalidation time. That is, it is determined that a waving operation isstarted when the acceleration signal output falls outside apredetermined threshold range (for example, the range of the thresholds±A or less in FIG. 5A), and it is determined that the titling operationis stopped when a state in which the acceleration signal output fallswithin the predetermined threshold range continues for a predeterminedtime (for example, the threshold E in FIG. 5A) or more. In this case,determination in S701 of FIG. 7 is performed for each axial direction(S9002 and S9009 in FIG. 8A and S9014 in FIG. 8B), and a process ofinvalidating the operation unit in S702 of FIG. 7 is performed inaccordance with the surface (S9003 and S9010 in FIG. 8A and S9015 inFIG. 8B).

Other Embodiments

In the first and the third embodiments described above, of theoperations of the operation devices, an operation corresponding to aninstruction to commence image capture (full stroke of the release button2001) is one that is not invalidated. However, an operationcorresponding to an instruction to commence image capture may also berendered invalid. In this case, in S8005 of the first embodiment,operation of all the operation devices is invalidated, and in S9003 ofthe third embodiment, operation of the operation devices provided on theupper surface of the camera, including the full stroke of the releasebutton 2001, is invalidated.

Aspects of the present invention can also be realized by a computer of asystem or apparatus (or devices such as a CPU or MPU) that reads out andexecutes a program recorded on a memory device to perform the functionsof the above-described embodiment(s), and by a method, the steps ofwhich are performed by a computer of a system or apparatus by, forexample, reading out and executing a program recorded on a memory deviceto perform the functions of the above-described embodiment(s). For thispurpose, the program is provided to the computer for example via anetwork or from a recording medium of various types serving as thememory device (e.g., computer-readable medium).

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions. Furthermore, the present invention is not limited to animaging apparatus. More specifically, each of the above-describedexemplary embodiments of the present invention can be implemented on anelectronic apparatus and a communication apparatus.

This application claims the benefit of Japanese Patent Application No.2009-030469, filed on Feb. 12, 2009, No. 2009-034027, filed on Feb. 17,2009, and No. 2010-027001, filed on Feb. 9, 2010, which are herebyincorporated by reference herein in their entirety.

What is claimed is:
 1. An electronic apparatus comprising: a firstoperation unit, which is provided on an outer surface of the electronicapparatus, configured to enable a user to input an instruction to theelectronic apparatus; a shake detection unit that detects a shake of theelectronic apparatus; and a controller that invalidates an operation ofthe first operation unit based on a direction of the shake detected bythe shake detection unit, wherein the controller invalidates anoperation of the first operation unit if the direction of the detectedshake is a first direction and does not invalidate an operation of thefirst operation unit if the direction of the detected shake is a seconddirection.
 2. The electronic apparatus according to claim 1, furthercomprising: a second operation unit, which is provided on an outersurface of the electronic apparatus, configured to enable a user toinput an instruction to the electronic apparatus, wherein, if thedirection of the detected shake is the first direction, the controllerinvalidates an operation of the first operation unit withoutinvalidating an operation of the second operation unit.
 3. Theelectronic apparatus according to claim 2, wherein, if the direction ofthe detected shake is the second direction, the controller invalidatesan operation of the second operation unit without invalidating anoperation of the first operation unit.
 4. The electronic apparatusaccording to claim 1, further comprising: a third operation unit, whichis provided on an outer surface of the electronic apparatus, configuredto enable a user to input an instruction to the electronic apparatus,wherein, if the direction of the detected shake is the first direction,the controller invalidates an operation of the first operation unitwithout invalidating a predetermined operation of the third operationunit, and wherein, if the direction of the detected shake is the seconddirection, the controller does not invalidate an operation of the firstoperation unit and an operation of the third operation unit.
 5. Theelectronic apparatus according to claim 4, further comprising: an imagecapture unit, wherein the third operation unit is to input aninstruction regarding image capturing using the image capture unit. 6.The electronic apparatus according to claim 5, wherein, if the directionof the detected shake is the first direction, the controller invalidatesan operation of the third operation unit to input an instruction tocommence image capturing preparation operations without invalidating anoperation of the third operation unit to input an instruction tocommence image capturing operations.
 7. The electronic apparatusaccording to claim 1, wherein the shake detection unit detects andoutputs an acceleration component of a shake of the electronicapparatus, and the electronic apparatus further comprising a directiondetermination unit that determines a direction of a shake applied to theelectronic apparatus based on the output of the shake detection unit. 8.The electronic apparatus according to claim 7, wherein the shakedetection unit is an acceleration sensor capable of detectingaccelerations in directions along with three-axes of a coordinatesystem, and wherein the direction determination unit determines thedirection of a shake applied to the electronic apparatus based on signsof outputs of the acceleration sensor and whether or not an absolutevalue of the output of the shake detection unit exceeds a firstthreshold.
 9. The electronic apparatus according to claim 2, wherein thefirst operation unit and the second operation unit are provided ondifferent outer surfaces of the electronic apparatus with each other.10. The electronic apparatus according to claim 2, further comprising:an orientation determination unit that determines an orientation of theelectronic apparatus, wherein the controller invalidates at least one ofthe first operation unit and the second operation unit based on theorientation of the electronic apparatus detected by the orientationdetermination unit and the direction of the shake detected by thedirection determination unit.
 11. The electronic apparatus according toclaim 4, further comprising: an orientation determination unit thatdetermines an orientation of the electronic apparatus, wherein thecontroller invalidates at least one of the first operation unit and thethird operation unit based on the orientation of the electronicapparatus detected by the orientation determination unit and thedirection of the shake detected by the direction determination unit. 12.A control method for an electronic apparatus having a first operationunit, which is provided on an outer surface of the electronic apparatus,to enable a user to input an instruction to the electronic apparatus,the control method comprising: a shake detection step of detecting ashake of the electronic apparatus; and a control step of invalidating anoperation of the first operation unit based on a direction of the shakedetected in the shake detection step, wherein the control stepinvalidates an operation of the first operation unit if the direction ofthe detected shake is a first direction and does not invalidate anoperation of the first operation unit if the direction of the detectedshake is a second direction.
 13. A non-transitory computer-readablerecording medium in which computer program that causes a computer toexecute the control method according to claim 12.